Aging, chronic diseases, and acute events such as a stroke and hip fracture result in a reduction in[unreadable] physiological reserve and functional decline The fundamental tenet of the Applied Clinical Physiology Core[unreadable] (RC-3) is that physical deconditioning and "learned" non-use propagate functional declines in older people.[unreadable] This provides a biological rationale to implement exercise training to improve multiple physiological systems[unreadable] in older persons hindered by disability. The mission of RC-3 is to provide a core for the standardized[unreadable] cardiovascular, functional, and metabolic evaluations of OAIC research subjects and assist investigators in[unreadable] determining the mechanisms by which exercise rehabilitation strategies enhance function and recovery in[unreadable] older adults with disabling diseases such as stroke or hip fracture. This Core focuses on the following aims:[unreadable] 1. To perform medical assessments and cardiovascular screening of research volunteers entering OAIC[unreadable] studies in order to ensure patient safety and eligibility.[unreadable] 2. To standardize the conduct of exercise physiology, body composition, and metabolism measures that will[unreadable] define the phenotype of disability by characterizing the pathophysiology and functional performance of[unreadable] older, disabled volunteers in OAIC research.[unreadable] 3. To assess whether the exercise rehabilitation interventions increase cardiovascular fitness and[unreadable] ambulatory physical activity levels, improve body composition and metabolic profiles.[unreadable] 4. To train junior faculty investigators in geriatrics and gerontology in the performance of applied exercise[unreadable] physiology research relevant to exercise -based rehabilitation, in disability and aging.[unreadable] 5. To provide an educational and consultative resource for all investigators interested in exercise[unreadable] rehabilitation in aging, and the assessment of exercise rehabilitation, cardiovascular physiology and[unreadable] ambulatory function in the OAIC.[unreadable] These specific aims represent an enrichment of the contributions that the core has made in the previous[unreadable] OAIC as well as a new CDP designed to determine the effects of exercise rehabilitation on functional[unreadable] performance in older adults infected with HIV, and new pilot and exploratory (P/E) projects and Junior[unreadable] Faculty Award (JFA) projects in stroke, robotics, and hip fracture. Thus, the RC-3 plays a critical role in[unreadable] integrating and linking the RCs, the CDPs, JFA projects, P/E projects in the study of exercise design, and its[unreadable] conduct, and the measurement of cardiovascular fitness, metabolism and body composition.[unreadable] Lay: The mission of the Applied Physiology Core (RC-3) is to assess the effects of exercise rehabilitation on[unreadable] exercise performance, ability to perform tasks of daily living, muscle and fat mass, and risk factors for heart[unreadable] disease in older subjects disabled by chronic stroke, hip fracture, and other disabling diseases.